1. Field of Invention
This invention generally relates to distance determination, particularly distance determination for space applications.
2. Related Art
Determining a distance to a particular object may be difficult in some circumstances. For example, it may be difficult to determine the distance (range) to an object in space. Distances of interest in space application range from a few meters to kilometers.
Existing ranging systems are passive or active systems. In a passive system, existing radiation is used. In an active system, radiation is generated by the system, reflects from the object of interest, and the reflected radiation is detected.
However, existing systems may be unduly complex or cumbersome. For example, active ranging systems generally have high laser power supply requirements and are detectable by counter-measures. Passive ranging systems generally require long baselines (for stereo ranging systems), and/or moving the measurement system. Additionally, systems that use object size or features to estimate range require the object to be very large or very close, in order to resolve it well enough to determine range.